Monday, July 7, 2014


Lens questions come up all the time and here's an answer to one of those: What to look for in a lens!

Debra,
 
Here's a "rating" of lenses" by DP Review and will show how both prime and zoom lenses did in their tests. I'm suspect, and surprised to see Canon out number the Nikons, which here on the DXO site, the Nikons show up in masse, way before the Canons! And the After Market brand, Sigma, is on top. The lack of Carl Zeiss lenses here on the DP Review also is suspect. Regardless, both of these listings/rankings will give you a sense of how lens makers try and produce the best possible quality and seldom acheive that goal, with each lens they design.
 
Carl Zeiss lenses, which you can purchase, for your Canon 5D MKIII, is $4,000, Zeiss Distagon T* Otus 1.4/55 ZF.2  and is arguably one of the World's finest lenses ever made.
 
 
And here's DXO's info:
 
 
As Paul,Andrew and Patrick pointed out and I mentioned, there will be choices to be made,when you are putting together your "kit". On a long list of parameters, I wouldn't have weight anywhere near the top. A pound here or there doesn't matter and you not hiking the Appalachian Trail,where ounces may make a difference. It's like carrying an extra water bottle. 
 
As a general rule,
 
1. Prime lenses will always be sharper than zooms, mostly due to the mechanics of the lens and and things moving in and out. Prime lenses don't move and remove one obstacle from the designers and the result, are amazing lenses,even less expensive prime lenses will out perform most zoom lenses.
 
2. The aperture generally indicates the relative quality of the lens. So a F4.0 lens will generally cost less than an F2.8 and a F2.8 lens will cost less than an F1.4 lens,generally!
 
3. With that said, an F2.8 lens will generally produce better images throughout it's range, but the "sweet spot" is usually closer to the middle numbers, F8,F11,etc. but again, really hard to see in actual use.
 
 So with those 3 statement above, used as the basis of what I'm going to say,let's try and answer your main question, "Rich, does buying the most expensive lens, guarantee me the sharpest images?" NO, not always and not if you don't use the best techniques to produce those images, but it will give you the opportunity to take the best images.
 
Another question: "Rich, How does the aperture at f/4.8 differ from the aperture at f/2.4 but more importantly is it worth the difference in cost which is quite a bit (I think so)? Will it make the difference between spending twice as much? You seem to imply that those factors don’t have any effect on the overall results and that only one’s expertise and personal technique can create any real effects that are satisfactory on the final results.?"
 
So there are a few questions here and I'll answer what I can. As I stated in #2, the aperture "hole" and in this case, let's say,is F2.8 and another lens you have is F4.0, doesn't make much difference in tha actual capturing of the image, landscapes,since with that wide angle and shooting landscapes, the actual aperture used will be almost ALWAYS towards the other end, F11,F16 or F22,etc. So the questions about taking images of landscapes with a wide angle lens and the largest aperture is either F2.8 or F4, doesn't really matter. Those aperture will be seldom used and if used, then the "softness" of the image, on either side of the focal point, is desired.
 
And furthermore, buying an inexpensive lens, with an aperture range of  F5.6 to F16, the resulting "sweet spot" wil be very narrow, like one f-stop,where on the more expensive lens, with a range of F2.8 to F32.0, the the "sweet spot" is much wider and that is what you're paying for.
 
So I hope this has answered a few of your questions and let me and the others here,know if you have other questions that we might be able to answer,
 
Rich

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